Labelling a bottle etc. has been conventionally conducted by picking up preliminarily cut labels one by one and putting them on the bottles etc. This method, however, has a fatal defect that there is a possibility that wrong labels or labels of different kinds may get mixed during setting of labels in a labelling machine. If the indication of a label is inconsistent with the contents of an article to which the label is affixed, the article is not marketable, and moreover it may possibly endanger a user's life in case the article is chemicals etc.
In this connection, it has been proposed, to eliminate any possibility of mixing of different kinds of labels, that a series of labels printed on a tape and wound into a roll be employed, being cut one by one just before labelling articles. In this method, it is required to repeat, at a high speed, feeding a tape by a length of one label, stopping the feeding, cutting the tape into a label, pasting the label and labelling an article such as a bottle etc. However, patterns for indication, such as marks or letters printed on the respective labels of the tape are not always of the same length because of expansion and contraction of the paper caused during printing, expansion due to a tensile force caused in feeding, or expansion and contraction according to weather of humidity. Accordingly, if the tape is cut after feeding thereof by a predetermined length in disregard of such possible expansion or contraction of the paper, only labels of the same length can be obtained but labels properly bearing patterns, such as marks or letters thereon can not always be obtained and the marks or letters may possibly get out of the position, spoiling the labels.
On the other hand, it is to be noted that since the present art level of cutting and pasting techniques can well meet a high speed labelling operation, the performance of the labelling machine is determined depending upon how quickly and accurately the labels fed at a high speed can be stopped at a required position according to the patterns printed thereon.
It is therefore an object of the present invention to provide a tape feeding apparatus which is capable of stopping the tape which is being fed at a high speed, accurately and surely at a required position in relation with marks or letters printed on the tape.
According to the present invention, there is provided a tape feeding apparatus comprising a rotary member for feeding a tape; a rotary shaft of the rotary member; at least two clutch means mounted on the rotary shaft and adapted to rotate said rotary shaft in one direction only; lever members connected to the clutch means, respectively, for effecting rotation of said clutch means; connecting rods pivotally connected to the lever members, respectively; rotary driving means; and means drivingly connecting the rotary driving means to said connecting rods and adapted to impart a reciprocating motion to the respective connecting rods according to the operation of the rotary driving means; said levers and said connecting rods being arranged in positions to rotate the respective clutch means at different speeds and with a phase difference according to the reciprocating motion of the connecting rods so that one of the connecting rods for a low speed rotation is set in operation just before another enters its dead point.